MECHANISMS OF HUMAN LUNG HYPERSENSITIVITY REACTIONS

人肺超敏反应的机制

• 批准号: 2061290
• 负责人: Edward Schulman
• 金额: $ 21.53万
• 依托单位: ALLEGHENY UNIVERSITY OF HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-01-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2061290
• 关键词: RNase protection assay; antiinflammatory agents; cell type; cellular pathology; corticosteroids; cytokine; enzyme inhibitors; gene expression; human tissue; immunocytochemistry; immunomodulators; in situ hybridization; indomethacin; inflammation; interleukin 4; interleukin 5; lipoxygenase; low density lipoprotein; mast cell; messenger RNA; polymerase chain reaction; prostaglandin endoperoxide synthase; respiratory hypersensitivity; respiratory pharmacology; stimulant /agonist

The central role of airway inflammation in chronic asthma has received increasing attention concordant with an alarming decade-long surge in asthma morbidity and mortality especially in urban populations where sizable numbers of asthmatics have elevated levels of IgE directed against indoor inhalants. The long term objective of this project is a better understanding of the cellular and molecular mechanisms of human lung allergic disorders and asthma, and means of their control. The human lung mast cell (HLMC) by virtue of its anatomic localization, elaboration of potent chemical mediators upon stimulation, and the effects of these mediators on cell and tissue targets, triggers the pathophysiologic manifestations of the acute ("early phase," EPR) asthmatic response that results in immediate breathlessness. It is unknown what cell(s) directly produces the groundwork for chronic airway inflammatory ("late phase", LPR) responses characterized by leukocyte, especially eosinophil, infiltration of airways. The current view, principally based on cell samplings obtained well beyond the initial development of airway inflammation, is that the LPR is "driven" by Interleukin-4 and -5, the major cytokines responsible for IgE generation and eosinophilia, respectively, emanating from the "Th2" subtype of cD4+ T-lymphocytes. We hypothesize that the mast cell is the major contributor of "TH2" cytokines released within 2-4 hours following allergen challenge, and thus sets the framework for chronic inflammation. Over the past twelve years, techniques developed in our laboratory to purify HLMC have allowed for the first time, detailed studies of their biology. Also, we discovered and physically separated HLMC subpopulations distinguished by morphologies, histochemistry, and function. Recently, we have applied molecular hybridization and protein quantification techniques to identify the gene expression, protein release and temporal pattern of co-expression from purified HLMC and lung tissue, of Th2 cytokines. Moreover, we have begun to uncover pharmacologic mechanisms regulating gene expression and release of IL-5, including the annihilation of the IL-5 mRNA and protein responses by corticosteroids. Our specific aims are to define "Th2-like" cytokines in purified HLMC, HLMC subsets, and human lung tissue fragments, with respect to: identification, quantification, triggers, and their drug modulation including corticosteroids, and 13-agonists. Gene expression will be screened using reverse transcription polymerase chain reaction (RT-PCR), and RNase protection. Cellular attribution of cytokine generation will be performed by in situ hybridization and immunocytochemistry. Increased understanding of HLMC heterogeneity, Th2 cytokine generation from human lung and purified HLMC, and the capacity of specific drugs to target "inflammation" and the LPR, will broaden our understanding of human hypersensitivity, and influence the construction of therapies.

气道炎症在慢性哮喘中的中心作用已经得到了 越来越多的关注与令人震惊的长达十年的激增相一致， 哮喘发病率和死亡率，特别是在城市人口中， 相当数量的哮喘患者具有高水平的IgE， 对抗室内吸入剂该项目的长期目标是 更好地了解人类的细胞和分子机制 肺过敏性疾病和哮喘，以及控制它们的方法。人类 肺肥大细胞（HLMC）凭借其解剖定位，阐述 刺激后的有效化学介质，以及这些介质的作用 介质对细胞和组织的目标，触发病理生理 急性（“早期”，EPR）哮喘反应的表现， 导致立即呼吸困难。目前尚不清楚哪些细胞直接 产生慢性气道炎症的基础（“晚期”， LPR）反应，其特征在于白细胞，尤其是嗜酸性粒细胞， 气道渗透。当前视图主要基于单元格 在气道初步形成后很长时间内获得的采样 炎症，是LPR是由白细胞介素-4和-5， 负责IgE产生和嗜酸性粒细胞增多的主要细胞因子， 分别源自CD 4 + T淋巴细胞的“Th 2”亚型。我们 假设肥大细胞是“TH 2”的主要贡献者 过敏原激发后2-4小时内释放的细胞因子，和 从而为慢性炎症奠定了基础。 在过去的12年里，我们实验室开发的技术， 纯化HLMC首次允许对其进行详细研究， 生物学此外，我们发现并物理分离HLMC亚群， 通过形态学、组织化学和功能来区分。最近， 我们应用分子杂交和蛋白质定量 技术，以确定基因表达，蛋白质释放和时间 来自纯化HLMC和肺组织的Th 2共表达模式 细胞因子此外，我们已经开始揭示药理学机制， 调节IL-5的基因表达和释放，包括 皮质类固醇对IL-5 mRNA和蛋白应答的消除。 我们的具体目标是在纯化的HLMC中定义“Th 2样”细胞因子， HLMC亚群和人肺组织碎片，关于： 识别、量化、触发及其药物调节 包括皮质类固醇和β-激动剂。基因表达将是 使用逆转录聚合酶链反应（RT-PCR）筛选， RNase保护细胞因子产生的细胞属性将 通过原位杂交和免疫细胞化学进行。增加 HLMC异质性的理解，Th 2细胞因子从人 肺和纯化的HLMC，以及特异性药物靶向 “炎症”和LPR，将拓宽我们对人类的理解 超敏反应，并影响治疗的构建。